class Config(object):
    DEBUG = False


class ProductionConfig(Config):
    pass


class DevelopmentConfig(Config):
    DEBUG = True
    SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://root:123@127.0.0.1:3306/flask_front?charset=utf8'
    SQLALCHEMY_POOL_SIZE = 5
    SQLALCHEMY_POOL_TIMEOUT = 30
    SQLALCHEMY_POOL_RECYCLE = -1
    # 追踪对象的修改并且发送信号
    SQLALCHEMY_TRACK_MODIFICATIONS = False
